how does dave singleman relate to the title of the play?

Dave Singleman symbolized what Willy dreamed of for his own funeral, as a testament to his life. He saw himself as surrounded by friends, who would be grief stricken at his loss. Singleman's death and subsequent funeral was the main reason Willy became a salesman.... he saw it as a way to make friends.... be well liked, respected, and admired. He judged the man by the size of his funeral and saw the crowd as a testament to success.